Types of Vision Loss

Visual Field Deficits and Vision Rehab Post Stroke or Brain Injury

Visual field deficits post stroke or brain injury are quite common. Various types of vision loss, such as hemianopia, quadrantanopia, scotoma, and low vision, affect approximately 28% of stroke survivors and approximately 20% permanently.1 In addition, visual and visual-cognitive disorders can negatively impact nearly all aspects of a patient’s vision – from balance to color recognition to the width of the visual field. Symptoms vary widely, ranging from subtle to dramatic.

Visual field deficits after stroke or brain injury can be overlooked early on as more severe, and life threatening, injuries sustained from the stroke or brain injury are treated. Patients should undergo a vision evaluation as soon as possible after their injury. Even if a patient does not perceive any problems with his or her vision, defects may be present, and they can have an extensive impact on the patient’s life and rehabilitation efforts.

Spontaneous Improvement and Recovery

Within three months of a stroke or brain injury, it is common for patients to experience spontaneous improvement and occasionally full resolution of their visual field deficits. In other words, some vision difficulties will clear up by themselves. In many cases, spontaneous recovery is partial and does not eliminate the need for formal vision rehab after stroke or brain injury.

However, stroke survivors are often left with lingering vision difficulties even after spontaneous improvement and require therapeutic intervention.

Alternative Therapeutic Strategies

There are three main strategies for potential visual rehabilitation:

Substitution: the use of optical aids whereby the sighted field can be extended towards the blind field. This is a coping strategy that does not increase sensitivity in the blind field but rather uses prisms to optically shift part of the visual space.

Compensation: using saccadic training, patients are trained to rapidly and continuously scan their surroundings in order to direct their gaze toward the blind field, bringing the previously unseen objects within their sighted field. NovaVision’s NeuroEyeCoach ™ is an internet-delivered, at-home computer based therapy which re-trains a patient to move their eyes, re-integrate left and right vision and to make the most of their remaining visual field.

Restoration: Restitution is the only therapy that provides actual improvement in the range or sensitivity of the patient’s field of vision. NovaVision’s VRT repeatedly activates dormant neurons that do not function properly in areas of partial injury (“transition zones”), strengthening residual vision and neuronal networks. Repetitive stimulation has proven effective in the recovery of other functions such as movements of lower limbs after stroke.

Two things happen when someone suffers from vision related disorders following a stroke or brain injury: there is a loss of visual field as well as difficulty with eye movement, affecting the ability to integrate visual information. While VRT addresses the restoration of lost vision, NeuroEyeCoach enables the patient to make the most of their remaining vision. The two therapies are therefore highly complementary and NovaVision provides them in a suite to ensure broad benefits to patients.

Types of Visual Field Deficits and Their Impact on Daily Life

Strokes and brain injuries are associated with several types of visual field deficits. These visual field deficits can include blind spots within vision, and other effects that can lead to difficulties in everyday activities. Vision rehab after stroke or brain injury can help address these deficits.

Hemianopia and Quadrantanopia

Hemianopia, also known as hemianopsia or visual field loss, is common among survivors of stroke and brain injury. It is defined as decreased vision or blindness in half of the visual field in one or both eyes. There are various types of hemianopia, including quadrantanopia (quadrantanopsia/quadrantic hemianopia), which is characterized by low vision or blindness in one quarter of the visual field.

Hemianopia’s Impact on Daily Life

Hemianopia and quadrantanopia are associated with the following problems:

Difficulty reading, watching TV, and performing other daily life activities

Increased risk of tripping, falling, bumping into objects, being struck by unseen objects, knocking over objects, and similar accidents

Difficulty keeping one’s place when reading

Being startled by people or objects that seem to pop out of nowhere

Difficulty crossing roads unaided

Difficulty being at home alone

Difficulty working

Difficulty driving

Scotoma

Scotoma is a visual blind spot occurring in any part of the visual field of both eyes. A scotoma can be an area of vision loss (darkness), lightness, blurring, or distortion. When a scotoma is in a person’s peripheral vision, it may have a minimal impact on day-to-day functioning; however, a visual blind spot in the center of the visual field (paracentral scotoma) can be debilitating.

Scotomas are associated with the following issues:

Limited mobility, especially if scotomas are large and/or numerous

Difficulty reading

Needing reading materials to be magnified, as well as greater illumination and contrast

Difficulty perceiving colors

Diffuse Field Defects and Low Vision

Diffuse visual field loss has a range of symptoms. Patients suffering from low vision may experience one or more of the following:

Overall blurring

Loss of central vision

Loss of peripheral vision / tunnel vision

Multiple field loss (seeing dark objects scattered around objects)

Low Vision’s Impact on Daily Life

Diffuse visual field deficits, or low vision are associated with the following problems:

Loss of independence and mobility

Inability to drive safely

Difficulty reading, watching TV, and using a computer

Vision Rehab Post Stroke / Brain Injury

Research into neuroplasticity in the vision center of the brain, as well as the subsequent development of advanced vision rehab technology such as the therapies offered by NovaVision, has given new hope to survivors of stroke and brain injury. It is important for patients and caregivers to keep the following points in mind:

Even if patients don’t perceive any problems with their vision, or their visual field deficits seem to spontaneously resolve in the months after their injury, it is important for them to be evaluated by a doctor in order to measure any vision loss, or eye damage that could have taken place. An evaluation can reveal visual field deficits, or other problems that patients didn’t know they had. In addition, an undiagnosed visual defect can undermine other rehabilitation efforts, have a devastating impact on daily life, and increase the risk of injuries resulting from poor vision.

Vision rehabilitation techniques such as NovaVision's Vision Restoration Therapy or NeuroEyeCoachTM may help a patient improve his or her vision, regardless of when the stroke or brain injury occurred. In addition, VRT can address visual field deficits that were previously considered untreatable.

Vision rehab can be an effective complement to traditional rehabilitation efforts, such as occupational and physical therapy. In addition, vision rehab can give patients a sense of independence and well-being, helping them successfully undergo rehabilitation, resume hobbies, and more.

The Differences between Substitution Compensation and Restoration for Vision Loss

There are three main strategies for potential visual rehabilitation:

Substitution

The use of optical aids whereby the sighted field can be extended towards the blind field. This is a coping strategy that does not increase sensitivity in the blind field but rather uses prisms to optically shift part of the visual space.

Compensation

Using saccadic training, patients are trained to rapidly and continuously scan their surroundings in order to direct their gaze toward the blind field, bringing the previously unseen objects within their sighted field. NovaVision’s NeuroEyeCoach ™ is an internet-delivered, at-home computer based therapy which re-trains a patient to move their eyes, re-integrate left and right vision and to make the most of their remaining visual field.

Restoration

Restitution is the only therapy that provides actual improvement in the range or sensitivity of the patient’s field of vision. NovaVision’s VRT repeatedly activates dormant neurons that do not function properly in areas of partial injury (“transition zones”), strengthening residual vision and neuronal networks. Repetitive stimulation has proven effective in the recovery of other functions such as movements of lower limbs after stroke.

Two things happen when someone suffers from vision related disorders following a stroke or brain injury: there is a loss of visual field as well as difficulty with eye movement, affecting the ability to integrate visual information. While VRT addresses the restoration of lost vision, NeuroEyeCoach enables the patient to make the most of their remaining vision. The two therapies are therefore highly complementary and NovaVision provides them in a suite to ensure broad benefits to patients.

To learn more about the various types of visual field deficits, vision rehab post stroke or brain injury, or how to begin vision therapy, please contact NovaVision by email or call us at 1.888.205.0800.